There are three different ways to overclock on the X99-UD4, the first and easiest is the auto tune feature in Gigabyte’s EasyTune software.
Upon running it out system reached an overclock of 4.10 GHz.
There are also pre-set overclock modes in the BIOS. Of course we went in and decided to do some manual overclocking. Bumping the voltage up to 1.40 I was able to get the system up to 4.4 GHz.
As you can see it looks like 4.4 GHz is the highest overclock we have been able to achieve on the X99 platform on all of the motherboards that we have tested.